1. Field of the Invention
The present invention is generally in the field of electronic circuits. More particularly, the invention is directed to power delivery circuits having load protection.
2. Background Art
An electrical system, such as an automotive electrical system, includes a power delivery circuit for providing power to electrical loads. Power delivery circuits often include electrical protection circuitry for protecting loads from unfavorable electrical conditions. One unfavorable electrical condition that can occur in an electrical system is a “reverse battery condition.” This can occur, for example, in an automotive electrical system, when a battery is undesirably connected to the electrical system with its terminals reversed from regular operating condition. Another such unfavorable electrical condition that can occur is a “load dump condition,” in which, a load is inadvertently disconnected from an electrical system, causing a substantial voltage spike in the electrical system. This can occur, for example, in an automotive electrical system when a terminal of a battery, driven by an alternator, becomes disconnected.
Conventional electrical protection circuits use FETs (e.g. MOSFETs) and surge suppressors to protect loads from unfavorable voltage conditions. For example, a FET can be cascaded with a load to be protected. However, because a FET comprises an intrinsic diode at a p-n junction, under reverse battery conditions, the intrinsic diode can become forward biased and a reverse voltage can be applied to the load, which can damage the components of an electrical system. In order to avoid this threat present in conventional electrical protection circuits that use FETs and surge suppressors, complex circuits might be needed, which increases manufacturing costs.
Thus, there is a need in the art for power delivery systems that can, for example, protect electrical loads in a reverse battery condition without a need for complex circuitry required to address the potential threats present in the conventional electrical protection circuits that are used, for example, in automotive electrical systems.